Gas burner



March 26, 1935. w. B. MAN'GoLD As @URNER 1 l'Film1 sept. 18, 195:5

, 2 Sheets-Sheet 1 3 J 2 6 9. W 1 .0 Af a, a s 9.4 3 f4 l Q7.

,Patented Mer. ze, 1935 UNITED STATES PATENT GFFICE GAS BURNER William B. Mangold, Chicago, Ill.; Mildredl. Mangold, administratrix of said William B. Mangold, deceased, assigner to The TrustCompany of Chicago, as trustee Application September 18, 1933, Serial No. 689,806

11 Claims.

ing plants and'in process and baking ovens subl' ject to automatic control, since when'once in-` -stalled and adjusted, it can vbe operated intermittently,. without danger .of flarebacks or ex- 'plosions upon relighting, It is accordingly an object of-this invention to provide an improved '1B gas burner'for the'purposes described that can "be intermittently operatedvby anautomatic on and off control. v

It is another object of this invention to vprovlde a gas burner, providing a gasand air mix- 80 ture that is projected'from and burns externally of the apparatus, whereby complete combustion can be obtained Without cooling the an'ie by adjacent metal surfacesv 'of the burner, or the provision of excess airbeyond that needed for lcombustion, since excess air tends to reduce the boiler or 4furnace efliciencydue to the heat carrriedaway thereby in the stack or chimney. It is also an`object of this-invention to`provide an improved combustion system for a gas burner 80 -whereinA a rich mixture of gas and airis prol*Jected as an annular, expanding cylinder withv secondary air supplies both inside and outside the burning mixture. WithA this arrangement, a

true Bunsen or colorlessflame results .differing 35 therefrom, however, in that the characteristicl .inner cone ofthe Bunsen flame is inthis case a cone of air supplying further oxygen to the interior ofthe hollow ring of lburning gas beyond the point of flame propagation'. The resulting colorlessflame'projects some distance from the burner without any *tendency to deposit soot uponv relatively cool surfaces in the neighborhood thereof or in the flues and stack of the boiler or 'oven in which it is installed. y

It is. a further object of this invention to provide an improved` gas burner having separately controllable air supplies permitting accurate ad.- justment of the primary mixture of gas 4and air and of the secondary air supplied to the burning mixture whereby complete control of the combustion -process may be had unaffected byvpossible variations in the gas supplypressure.

I It is still another -object of this invention to provide an improved gas burner with multiple 55' air supply connections under controllable pressures adjustable to produce air .velocities in proportion to the rate of flame propagation at the .burner nozzle.

It-is a further object of this invention to provide an improved and simplified high eiiciency gas burner that can be economically manufactured and accurately adjusted to the varying requirements of different types of gas available, i

such as natural and artificial gas and mixtures thereof.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings: I

Figure 1 is a side elevation of' a gas burner system embodying the features of this invention.

Figure 2 is a fragmentary enlarged longitudinal section through the gasburner of this invention.

Figure 3 is an end View from the right of' Figure 2.

Figure 4 is an elevation similar to Figure 1 but disclosing the use of separate blowers for the supply of air to the different passages in the burner.

. Figure4 5. is an end view of the nozzle outlet from the gas supply chamber.

Figure 6 is a section-on the une vI-VI or Fig- Figure 7 is a fragmentary elevation of one of the air supply pipes showing the damper con-` trol thereof.

Figure 8 is a section on the line VIII-VIII of Figure 7.

As shownby the drawings:

The present invention is illustrated as a com- 'plete burner unit intended to be used with auto'- matic temperature and operating controls, although the latter have not been illustrated in connection with the burner.

In describing the burner structur it will be convenient to refer first to Figure 2, wherein a series of concentric passages are provided by spaced tubes. Starting from the left in this gure, a centralV tube 10 is supported in an end closure 11 which has a spaced tubular extension 12 surrounding the .tube 10. A housing 13 provides an air chamber 14 having an outlet through a second spaced tube 15 supported by a diaphragm 16 between the housing 13 anda second housing 17 forming an airchamber 18. The chamber 18 has an outlet through a third spaced tube 19,

the same.

supported by an end closure 20. A fourth tube 21 envelops the tube 19 and has a collar 22 threaded at 23 on the rear of the tube 21 and secured to the tube 19 to from a closure, the arrangement preferably being such that the tube 21 can be rigidly mounted in an orifice leading to the combustion chamber' or fire box of a boiler or oven, and the balance of the burner applied or removed a's a unit by screwing the collar 22 onor offthe threads 23 of the tube 21. A

The tubes 15, 19 and 21 preferably terminate in the same plane and the central tube l0 projects somewhat beyond this plane in order to give stability to the ignition zone surrounding The tube 12 terminates about halfway of the tube and the space 24 between the tubes 10 and 12 is supplied with gas through a connection 25.- leading throughfthe end closure 11. The tube 12 terminates in a slotted nozzle 26 shown in Figures 5 and 6, the slots 27 therein .being preferably inclined as shown to set up a spiral flow in the gas. A double conical screen 28 is positioned in the space 29 between the tubes 10 and 15 outside the nozzle to facilitate mixture of air from the chamber 14 and gas leaving the nozzle 26. The screen serves primarily as a mixing device, since the burner is.

inherently free from danger of flare-backs for reasons to be brought out hereinafter, but would help to prevent such flare-backs should they occur. For convenience in what follows, the chamber 14 and the space 30 between the tubes l2 and 15 will be` referred to as the primary air supply and the space 29 as the mixing chamber for the gas and primary air supply; while the central tube l0, the space 31 between the tubes 15 and 19 and the space 32 between the tubes I9 and 21 as the secondary air supplies.l

In the form of Figure 1, `a single blower 33 supplies air through a connection 34, containing a valve indicated by its control handle 35, to an air manifold 36, from which connections 37,` 3,8, 39 and 40 lead to the tube 10, air chambers 14, and 18. and tube 21, respectively, each connection containing a butterfly valve 41 on a shaft 42 having a control knob 43 on one end and a spring ratchet 44 and wheel 45 on the other end, as shown in'Figures 'l and 8. The valve indicated by its handle 35 in the connection 34 is of the same construction; hence is not shown in Fig- The structure of Figure 4 differs from that of Figure 1 in that a lmotor 46 drives two blowers' 4'7 and 48, the smaller blower 47 supplying thel airchambers 141and 18y through a manifold 49,

.while the larger-blower 48 supplies the tubes 10 andl 21sW'Ihe` larger blower supplies increased pressure and volume which Ais desirable when handling gases of high heat value, such as natural. .gas and mixtures thereof with other gases, since agreater pressure and volume of air is required for proper combustion, and thisgreater vvolume should. besupplled through the secondary air' f` suppliesv for maximum combustion efficiency as w'ell as'stability of-flam'e propagation,

i In' the operation of this burner, thegas supply isyof course,`u nder the` control of a valve (not i "showm whlcntis adjusted, along with the valve in the connection 38, to provide the desiredl volume of rich mixture of gas and air in the. mix-4.

` ing chamber zaaccordmgto the dutyirequireci ofthe burner.

.duty may vary over wide limits in a given burner 1 It is to be understood that this I due Yto Avarying installation demands. After the desired volume of mixture hasQbeen determined,

the air supplies through the central tube1 1G and.

tube 19vare then adjusted by the valves in the connections 37 and 38 to provide a velocity therethrough approximating the rate of vflame propagation in the mixture. Then the air supply.

through the connection 40 isarranged to give a colorless flame indicative of complete and efficient combustion. It is to be noted at this point that by analysis of the products of combustion, the burner can be adjusted very accurately to eliminate carbon monoxide while reducing the amount of excess air, indicated by the presence of un-l off the gas and current supply to the blower movtor at the same time and the residual air pressure serves to evacuate unburned gas from the burner after the gas supply has been cut off.

The air supplied through the connection 40 to the tube 21 is not required with some types of gas, or at low combustion rates. Under these conditions, the tube 21 can be omitted, as sufllcient air can be supplied through the tube 19 without requiring a velocity exceeding that of the rate of flame'propgftion. While the burner of this invention can readily be adjusted for efficient combustion over a wide range of operating conditions, it is not the primary-intention to so control the burner in service, but to operate it intermittently at a fixed adjustment most satisfactory for each particular installation.

` In adjusting the burner for high rates of combustion where a long horizontal flame is desired, the air supply through the central tube 10 can be increased in velocity toa degree exceeding the rate of flame propagation, since the tube 10 projects beyond the ignition zone and therefore will "fore, do not purpose limiting tHe patent granted hereon otherwise than necessitated lby the prior art.

I claim as my invention:A

1. A gas burner'comprising a casing having a Iplurality of concentric air passages, an intermediate gas -supply passage` arranged to dis-l charge intoa mixing chamber in one of said air passages vsubject to suction produced by the flow of air in said air passage, means for supplying air under pressure to Yeach'of said concentric air-passages, and means for individually controllingthe supply of air to'each of said air passages.'

2. A gas burner comprising acasing having a plurality of concentric air passages, an intermediategas supply passage arranged to discharge into a mixing chamber in oneof said air passages subject to Asuction produced yby the .flow ofair in saidair passage, a mixing screen in said last mentioned airv passage, means for supplying air.

under pressure to each of .said concentric air passages, and .means for individually controlling and means for individually controlling the supply of air to each of said air passages.

4. A gas burner comprising a casing having a plurality of concentric air passages, an intermediate gas supply passage having a turbulence inducing outlet arranged to discharge into a mixing chamber in one of said air passages, a mixing screen in said last mentioned air passage, means for supplying air under pressure to each of said concentric air passages, and means for individually controlling the supply of air to each of said air passages.

5. A gas burner comprising a casing having a central tube and a series of concentric tubes arranged to provide a plurality of annular passages about said central tube, means for introducing gas into the tube outside the central tube, said means being subject to'suction induced by air ilow in said passage, means for supplying air under pressure to all of said tubes, and. means for controlling the supply of air to each of said tubes.

6. A gas burner comprising a casing forming an air chamber, an end closure having a tube extending through said air chamber and a gas connection through said end closure to said tube, a central tube extending axially through said iirst mentioned tube, a restricted gas outlet between the end of the iirst tube and the perimeter of the central tube, a diaphragm forming the other end closure for said casing, a second tube enveloping thegas'tube and the central tube and providing an outlet from the air chamber for air to be mixed with gas from the iirst tube, a second casing abutting the diaphragm and forming a secondair chamber, a closure for the free end thereof, a third tube enveloping the second tube and providing an outlet from the second air chamber, and means for supplying air to the.

several tubes.

7. A gas burner comprising a casing forming an air chamber, an end closure having a tube ex' tending through said air chamber -and a gas connection through said end closure to said tube, a. central tube extending axially through said rst mentioned tube, a restricted gas outlet between the end of the rst tube and the perimeter of the central tube, a diaphragm forming the other end closure f or said casing, a second tube enveloping the gas tube and the central .tube

and providing an outlet from the air chamber for air to be mixed with gas from the iirst tube, a second casing abutting the diaphragm and forming a second air chamber, a closure for the free end thereof, a third Vtube enveloping the second tube and providing an outlet from .the second air chamber, means for supplying air to the severalV tubes, and 'means for separately regulating the air supply to the tubes and air chambers.

8. A gas burner comprising a casing forming an air chamber, an end closure having a tube extending through said air chamber and a gas connection through said end closure to said tube, a `central tube extending axially through said first mentioned tube, a restricted gas outlet be'-` tween the end' of the first tube and the perimeter of the central tube, al diaphragm forming the other end closure for said casing, a second tube enveloping the gas tube and the central tube and providing an outlet from the air chamber for air to be mixed with gas from the first tube, a second casing abutting the diaphragm and forming a second air chamber, a closure for the free end thereof, a. third tube enveloping the second tube and providing an outlet from the second air chamber, a fourth tube enveloping the third tube, and means for supplying air to the several tubes.

9. A gas .burner comprising a casing forming an air chamber, an end closure having a tube extending through said air chamber and a gas connection through said end closure to said tube, a central tube extending axially through said iirst mentioned tube, a restricted gas outlet between the end of the first tube and the perimeter of the central tube, a diaphragm forming the other end closure for said casing, a second tube enveloping the gas tube and the central tube and providing an outlet from -the air chamber for air to be mixed with gas from the first tube, a second casing abutting the diaphragm and forming a second air chamber, a closure for the free end thereof, a third tube enveloping the second tube and providing an outlet from the second air chamber, a fourth tube enveloping the third tube-means for supplying air to the several tubes, and means for separately regulating the air supply to the tubes and air chambers.

1 0. A gas burner comprising a casing forming an air chamber, an end closure having a tube extending through said air chamber and a gas connection through said end closure to said tube, a central tube extending axiallythrough said first mentioned tube, a restricted gas outlet between the end of the rst tube and the perimeter of the central tube, a diaphragm forming the other end closure for said casing, a second tube enveloping the gas tube and the central tube and providing an outlet from the air chamber for air to be casing abutting the diaphragm and forming a second air chamber, aclosure for the free end thereof, a third tube enveloping the second tube and providing an outlet from the second air chamber, blower means for supplying air to the several tubes, means for regulating the blower pressure, and means for regulating the separate supplies to the several tubes.

vmixed with the gas from the first tube, a second ing the gas tube and the central tube and providing an outlet from the air chamber for air to be mixed with gas from the rst tube, a second casing abutting the diaphragm and forming a second air chamber, a closure for the free end thereof, a third tube'enveloping the second tube and providing an outlet from the second air chamber, a fourth tube enveloping the third tube,

blower means for supplying air to the several tubes, means i'or regulating the blower pressure and meansv for regulating the separate supplies to the several tubes.

WILLIAM B. MANGOLD. 

